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Incorporate diagnostic tests into your program. One convenient mechanism for this is the   The assert() macro is one convenient mechanism for interactive programs.

The assert macro expands to a void expression:

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In the following example, the test for integer wrap has been omitted for the on unsigned multiplication based on the assumption that MAX_TABLE_SIZE * sizeof(char *) cannot exceed SIZE_MAX. While we know this is true, it cannot do any harm to codify this assumption.

assert(size <= SIZE_MAX/sizeof(char *));
  table_size = size * sizeof(char *);

Note that this technique may not be suitable for server programs or embedded systems.  A failed assertion could lead to denial of service if a hacker discovered how to trigger it, e.g. if size were in some way derived from client input.  In such situations, a soft failure mode such as writing to a log file is more appropriate.

if (size > SIZE_MAX/sizeof(char *)) {
  fprintf(log_file, __FILE__ ": size %u exceeds SIZE_MAX/sizeof(char *)\n", size);
  size = SIZE_MAX/sizeof(char *);
}
table_size = size * sizeof(char *);

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